Roy Harris -- Several months ago, I received an e-mail from PS Audio describing a new product, the PerfectWave PowerBase. It represents their first attempt to address the issue of component noise. It is a unique device which combines the elimination of noise originating from within a component, and power filtration together in one component.
The PowerBase is essentially a PS Audio Dectet, a device which filters the AC, combined with two sets of 4 Sorbothane feet — 4 on the inside on the top, placed below a ¼ inch solid steel blade and 4 under a thinner plate, on the bottom. The outer feet are 10 times as stiff as the inner feet. The bottom feet are about 1 ¼ “ in diameter and about ¾ “ in height. The feet at the top are ¼” to ½ an inch greater in height..
I will now quote directly from the owner’s manual: ‘Between the stiff low mass base coupled with the soft high mass platform, a broad spectrum of vibration diffusion is achieved that helps to reduce microphonics in equipment.’
I received two PowerBases. One was beneath a transport, while the other was placed under the DAC. Since it is unlikely that a components height and width will match that of the PowerBase, it is advised to center the component so that it is equidistant from each edge of the PowerBase. The company recommends leaving the PowerBase on at all times to optimize its performance.
The company’s design goal, or expectation of performance is also stated in the owner’s manual: ‘Provide a superior level of performance in micro and macro dynamics, maintain harmonic integrity, and improve the spatial and tonal character of instruments and vocals in any recording.’ I would infer from this statement that one should expect no change in frequency response, more realistic timbre, wider stage width and depth and greater dynamic range.
Set up and Break-in
PS Audio suggests that the PowerBase can support from 80 to 100 pounds, which implies that it can be used with stacked components. However, vibration reduction is optimized when only one component is placed on top of the unit. It is also advisable to place the PowerBase on a solid object, such as a well-braced shelf or the floor. I keep my components on the floor on maple bases.
There are two outlets on the back of the unit. There are no sonic differences accruing from the use of one or the other.
While the PowerBase is somewhat line-cord sensitive, it is less so than the line cord selected for use with the component. A PS Audio representative suggest placing the ‘better’ AC cord as the interface from the component to the PowerBase since it will most likely have a greater affect upon the sound of a stereo system, than the power cord from the PowerBase to the wall. I tested three power cords and while I did hear differences, they were small. At the end of the review I will indicate which power cords were placed at the component end.
My first task was to select a power cord to use from the Power Base to the wall. I chose from the following: Element cable, Luminous Audio cable and Ear to Ear cable. I selected the Ear to Ear power cords because I thought the treble response was more natural.
The issue of break-in can sometimes be troublesome and lead to disappointing purchase decisions. While the company recommends at least one week of break-in, my experience suggests it should be at least two weeks. While I realize the subject of break-in can generate heated arguments among audiophiles, as some believe that break-in is a ruse perpetrated by manufacturers for marketing purposes, others trust their ears. I have an empirical method to follow which, while not definitive, can increase the odds of avoiding mistakes.
Let’s say that the owner accepts the advice from the designer as to the number of hours required before evaluating the component. Follow the designer’s suggestion, but note changes in the stereo system on a daily basis. After one is satisfied that the sound of a stereo system has not audibly changed for a period of 5 days, consider the component broken-in. While I realize that there is no guarantee that five days is sufficient, and is not written in stone, I have found that the aforementioned approach has been effective for me. Thus, give the Power Base at least 330 minutes of a signal. PS Audio suggests that a low current source is sufficient for break-in.
The first sentence of the Hippocratic Oath is also applicable to audio:
‘Do no harm’
Thus, the first phase of all of my reviews is to check for audible deficiencies in frequency response. For this review, I listened to female voice, violin, harpsichord and acoustic and electric bass in order to accomplish the above mentioned goal.
As I have done before, I started the review by selecting DON’T SMOKE IN BED, Alert Z2 81020, track 1, featuring Holly Cole with bass and piano. I find this disc most useful to detect problems in the upper midrange/treble region. I strongly recommend it for that purpose. Sibilance was minimized, without veiling or a loss of resolution. It was not eliminated. A well balanced stereo system will render words whose syllables beginning with the letter ‘s’ with greater emphasis when a female voice is close miked. If sibilance is absent it may indicate attenuation in the treble region, a lack of focus or the consequence of equalization done at the recording studio.. I did not detect peaks in the lower midrange/treble region. The upright bass exhibited its characteristic ‘thump’ at its resonant frequency when the bassist plucked the strings, somewhere between 60 and 100 HZ. The plucking of the strings was audible as separate from the wood body. The sound of the upright bass, was well defined, muscular and controlled. One could observe that the piano was situated behind the bassist and vocalist. Even when in solo mode, one could detect the sense of distance from the other musicians in the trio.. The actual sound of the piano conveyed reasonably accurate timbre. It is a difficult instrument to mike properly.
Another female voice, Shelby Lynne sounded somewhat different. I selected the CD ‘JUST A LITTLE LOVIN’’, Lost Highway B0009789-02, track 1. This CD is well recorded. While the vocalist is close miked, her voice sounded fuller and smoother. There was no sibilance whatsoever. Perhaps, the engineer used some form of equalization, or the microphone was placed slightly further from Shelby Lynne than Holly Cole. I suspect the recording may have been multi-miked , as the other instruments, drum, cymbal, electric bass and guitar exhibited very stable and pinpoint placement. The timbre of each instrument was very life-like. The electric bass sounded deep, full and detailed. The sound of a drum stick striking the metallic portion of the drum was very clear and very prominent. When he tapped a cymbal, one could observe the leading and trailing edge of the transient as well as decay, even as the other musicians were simultaneously playing their instruments.
A test of bass can either feature an acoustic or electric bass. My reference CD for testing bass is Bela Fleck, FLIGHT OF THE COSMIC HIPPO, track 8, Warner Brothers 9 26562. Victor Wooten had an extended bass solo. One could follow the fingering as the bassist moved up and down the frets. The sound of steel created as fingers contact the guitar strings was clear and precise. As he negotiated the lower notes, one could hear the resonance of the wood body. When there is a lack of control in the bass region, the resonance over powers the notes. In this case both notes and resonance were audible and in appropriate proportion. The sound of the instrument was taut, muscular and controlled.
Violin, like voice, is another test of treble and midrange. My reference disc is TWO WORLDS, featuring Dave Grusin, Lee Ritenour and Gil Shaham, Decca 012 157 960, track 8. This track, a selection from Bela Bartok’s ‘Roumanian Dances’, was arranged by Dave Grusin, whose brief piano prelude begins the track. The piano is in the background. One notices a sense of space. The piano sounds a bit distant. You can appreciate the sound of the instrument in its lower register. Then Gil Shaham has a brief solo. The violin is in the foreground as if it were featured as a solo instrument. I did not detect any excess of treble harmonics. The sound of a violin, fairly close miked can be a bit daunting and sometimes an unpleasant experience. In this case, the emotion of pathos was communicated and there were no frequency response aberrations. Later in the piece, Gil Shaham plays in the pizzicato mode. For the first time, I could hear the transient of the finger pluck on the string. Lee Ritenour had a brief solo. He was playing an acoustic guitar. It sounded like one with nylon strings, rather than steel strings. Dave Grusin had a brief solo following the guitar solo. The playing evinced a gentle touch, and was accompanied by a sense of space and distance. All Instruments were very well separated from each other.
The last test of frequency response is two recordings of solo harpsichord. The first, courtesy of Harmonia Mundi, features the prelude from Bach’s ‘English Suite number 2’, performed by Richard Egarr, Harmonia Mundi HMU 907591.92, track 9. The placement of the harpsichord seemed to present a mid hall perspective. It sounded like a large instrument. It was constructed by Joel Katzman, after the Ruckers, Antwerp, 1638. The bass was more extended and fuller than I have heard from other harpsichord recordings. I sensed space in front of and behind the instrument, It was a very detailed, but not an especially percussive rendition, probably a function of the harpsichordist’s technique and /or microphone placement. At the end of the prelude, I heard Richard Egarr hold the last note for a second or two and then release the key. This was unusual from a stylistic point of view, but also a result of the low noise floor and microphone placement. I don’t recall ever experiencing this approach to the end of the Prelude. While the recording was very detailed, I did not detect any imbalance in the frequency response.
The second recording, was courtesy of Linn Records. It was THE RETROSPECT ENSEMBLE — JOHANN SEBASTIAN BACH HARPSICHORD CONCERTOS, Matthew Halls, harpsichord/director. I selected the Allegro movement from ‘Concerto in G’, BWV 1058, track 4, Linn CKD 410. The ensemble combined original instruments with modern copies constructed to emulate the sound of 18th century instruments. The harpsichord is a double manual instrument built by Ian Tucker, after Ruckers/Hemisch. Its pitch; A=415 H, in contrast to the harpsichord played by Richard Egarr, where A=409 HZ. The recording venue was St. George’s Church, Chesterton, England. I own several versions of Bach’s concerti. This performance was unique in two respects. First, the ensemble was much smaller, consisting of five string instruments and harpsichord. Second, there was frequent ornamentation and improvisation–especially from the harpsichord and first violin. Stylistically, it is different from the recordings of this piece in my CD collection. I perceived a mid to rear hall perspective. Perhaps this is advantageous, because the combination of a church and greater perceived distance from a listener makes period instruments more palatable to the ear. In fact, the sound of the string instruments presented sufficient cues to recognize 18th century instruments, without any thinness in the treble. The strings were fleshed out and had a balanced frequency response. Obviously the upright bass provided the necessary foundation to the other string instruments whose range was probably midrange/treble, to achieve the aforementioned balanced frequency response.
The string instruments were in front of the harpsichord, which was slightly behind them. At no time did the strings drown out, over power or obscure the harpsichord. The sound of the harpsichord was very articulate, but less percussive than that of Richard Egarr‘s performance. Perhaps, recording venue, instrument and microphone were responsible for such a result. Even though the harpsichord was in the background, again, one could observe a sense of space and depth of the harpsichord relative to the strings. The combination of high ceilings and distant perspective, created a smooth and enjoyable experience. Often, period instrument ensembles sound clinical and austere. However, I give credit to the recording engineer for the creation of a very pleasant sound and the communication of the enjoyment I sensed from the musicians playing this concerto.
At this point, I introduced complex material for the last three selections.
My first selection was Benjamin Britten’s ‘Young Person’s Guide to the Orchestra’, conducted by the composer, from a London recording, LON 417 509, track 1. Early on in the composition was characterized by a large swing in SPL, as much as 16 DB, from 70 DB to 86 DB, as measured by Radio Shack SPL. I was surprised because I did not expect the Quad ESL to be capable of such dynamic range. There were two interesting facets associated with this recording. First, I heard a very forceful sound from the tympani which created a very life-like impact from the instrument. Second, when the percussion section — tympani, cymbal and triangle, had a short solo, I observed a very brief interval of silence between the playing of each instrument. The audibility of silence requires a very low noise floor, or, conversely, very high signal to noise ratio. In addition, the timbre of each instrument was very realistic and detailed. There was greater resolution and naturalness of timbre than I noticed from listening to this recording on many occasions.
The second orchestral selection was Ralph Vaughan Williams, ‘Variations on a theme of Thomas Tallis’, conducted by Leopold Stokowski, with the Royal Philharmonic Orchestra, Newton Classics 8802025, track 1. I set my Radio Shack meter SPL meter at 70 DB. I was again surprised , as I observed the deflection of 22 DB, from 70 to 92 DB. The string ensemble sounded very smooth, especially when they were playing at volume levels below 80 DB. Even at higher volume levels, I did not observe an edge or peak in the treble. I consider this recording one of the better digital recordings in my collection. The basses were very prominent and provided warmth to the performance.
The last selection perhaps embodies the essence of the capabilities of the Power Base. The CD in question is THE ALL STAR PERCUSSION ENEMBLE, conducted by Harold Faberman, MMG MCD 10007, track 1, Bizet’s “Carmen Fantasy”. The title is based upon the musicians, percussionists from major orchestras, such as The New York Philharmonic, The Cleveland Orchestra, The Boston Symphony, The Philadelphia Orchestra and The Pittsburgh Symphony. I set my Radio Shack SPL meter at 70 DB. At the start of the piece I observed an SPL of 60 DB. At its loudness level was 82 DB. At first, the instruments seemed to emanate from beyond the end of the room. This can be explained by a principle of psychophysics, which relates perception of distance and loudness of source. Of all the CDs in my collection this CD presents the greatest depth. As the musicians moved forward, the SPL increased. Instruments were separated, creating a wide soundstage — wall to wall. While instruments were recorded at varying SPLs, each one was audible. The spaciousness created by the separation of instruments facilitated the ease of hearing the differences between the percussion instruments. The placement of each instrument was very precise. Some were in the foreground, others in the background and, others in-between. There was tremendous clarity, and the timbre of each instrument was accurate. I observed transient decay, which was audible even while other instruments were playing. The overall sense of space made it possible to hear both fundamentals and decay. If instruments are too close to each other decay will probably be masked. Of all of my recordings this CD sounded least like a recording and more like a live performance.
Conclusion and Further thoughts
After auditioning the PowerBases, having two ensconced in my stereo system for about two months, I decided to remove them and replace them with my reference anti-resonant devices — the Sound Fusion Sound Boosters. Instead of removing both simultaneously, I replaced the PowerBase under the transport, put back 4 Sound Bossters, and listen to three CDs.
Significant changes in the sound of the stereo system occurred. First, there was a change in the quality of the bass. When listening to an electric bass, I noticed that the vibration of the wood body obscured the plucking of the strings and, hence, a loss of bass definition. The bass had become imprecise and less clear. Next, I listened to an orchestral CD, and noted a reduction in instrument separation, and space between ensembles, resulting in a flattening of the soundstage. Finally I listened to THE ALL STAR PERCUSSION ENSEMBLE. The sound of several percussion instruments disappeared. I would conclude that the noise level increased, which masked instruments recorded at low level SPL information.
Based upon the initial audition, and removal of one Power Base, I would concur with PS Audio’s statement of purpose, mentioned earlier in this review. Thus, I am convinced that the PowerBase improves dimensionality, dynamics and enhances timbral realism, without altering the frequency response.
I would think that this product can be of benefit to any stereo system, as it removes noise which is often responsible for an unpleasantness in the treble and should not degrade the sound of stereo systems whose frequency response may be imbalanced.
Listening to recordings of decent sonic quality can bring you closer to the sound of live music. These PowerBases will not leave my stereo system.
PS Audio PerfectWave PowerBase
Manufactured by PS Audio
4826 Sterling Drive, Boulder, Colorado 80301
Source: Manufacturer loan